One of the most important yet frequently neglected items in an internal combustion engine of the type having a crankcase containing a supply of oil is the maintenance of that oil supply at a proper level. This phenomenon is particularly evident in automobiles and trucks, but is also observable in other devices such as lawn mowers and motorcycles.
Periodic checking of the lubricating oil level in the engine crankcase to prevent it from falling below a predetermined level is important because forgetting to make such checks can lead to serious damage to the engine if the oil level drops below the predetermined level. At present, this checking relies on the engine user who must periodically check the level of oil and, if necessary, replenish it to its proper level. Such checking in most engines is accomplished by manual checking of the crankcase dipstick. However, in many engines the dipstick is either hard to locate or, once located, is positioned in the engine so that it requires the engine user to soil his or her hands and/or clothes on adjacent engine components while gaining access to the dipstick. Furthermore, in order to obtain an accurate reading of the level of oil present in the engine at a given time, after its location the dipstick must be withdrawn from the crankcase, wiped free of excess oil, reinserted, withdrawn again, and read. These inconveniences cause many engine users to neglect checking, either purposely or inadvertently, the oil level in their engines. Forgetting to make such oil level checks can lead to serious damage to the engine necessitating costly repairs or replacement and aggravation to the owner of the vehicle engine.
As mentioned above, this problem is most evident in automobiles and trucks, with the increasing scarcity of full-service gas stations and the advent of the self-serve station exacerbating the problem.
Numerous devices for automatically maintaining the oil level in the crankcase of an internal combustion engine are shown in the known prior art. However, these known devices all have at least one and in some cases many of the disadvantages listed below, which are believed to be eliminated by my invention. These disadvantages include lacking means for compensating for overfilling of the engine crankcase when the crankcase is in an unlevel position, requiring costly valves which are subject to mechanical failure for operation of the system or to allow the make up oil reservoir to be filled with oil, not providing means for visually checking the oil level without manipulation of a dipstick, not automatically maintaining the engine oil level, not providing means for refilling the make up reservoir without the oil running into the crankcase, requiring expensive electronic devices which are subject to failure for alerting the operator to low levels of oil in the crankcase, requiring heating of the make up reservoir by the engine for proper operation of the system, and requiring alteration of the engine crankcase for installation of the system. Some examples of known prior art oil level maintenance systems are shown in U.S. Pat. Nos. 635,210; 797,046; 1,105,894; 1,122,607; 1,171,223; 1,194,453; 1,317,961; 1,465,167; 1,705,845; 2,564,230; 2,615,442; 2,946,405; 3,712,420; 3,777,852; 4,091,894; 4,091,895; 4,108,201; and 4,603,666.
There is no automatic oil level maintenance system for an internal combustion engine of which I am aware which maintains the oil level in the crankcase of an engine without utilizing expensive components, which indicates the level of oil therein by visual inspection of the make up oil reservoir, and which is quickly and easily installed.